code: def test_expr_consts():
      """Test all constants defined in expr.consts"""
      name_map = {val: key for key, val in expr.consts.NAME_MAP.items()}
      for constname in expr.consts.__all__:
          const = getattr(expr, constname)
          z = const * datum.xxx
          assert repr(z) == "({} * datum.xxx)".format(
              name_map.get(constname, constname)
          )
  
file_path: altair/tests/expr/test_expr.py
imports: import operator
  import pytest
  from altair import expr
  from altair import datum
  from altair import ExprRef
  from jsonschema.exceptions import ValidationError
label_desc: Use image node_id 5 for calling a global function with example usage: test_expr_consts() without return types